RESUMO
BACKGROUND: Radiation-induced lung disease is a potentially fatal, dose-limiting toxicity commonly seen after radiotherapy of thoracic malignancies, including breast cancer. AIM: To evaluate and compare the early lung toxicity induced by 3D-CRT and IMRT radiotherapy treatment modalities in breast cancer female patients using biochemical, dosimetry and clinical data. SUBJECTS AND METHODS: this study included 15 normal healthy controls, 15 breast cancer patients treated with IMRT, and 15 breast cancer patients treated with 3D-CRT. One blood sample was obtained from the control group and 3 blood samples were withdrawn from cases before RT, after RT and after 3 months of RT. RESULT: IMRT delivered higher radiation dose to the breast tumor and lower doses to the lung as an organ at risk. There was a non-significant increase in the serum levels of IL-6 before IMRT and 3D-CRT compared with its levels in the control group. There were significant increases in serum levels of IL-6 after RT (IMRT and 3DCRT) compared with its levels before RT. There was a non-significant decrease in the serum levels of IL-6 after 3 months of RT (IMRT and 3D-CRT) compared with its serum levels immediately after RT. There was a non-significant increase in the serum levels of SP-D before RT (IMRT and 3D-CRT) compared with its levels in the control group. There were significant-increases in serum levels of SP-D after RT (IMRT and 3D-CRT) compared with its levels before RT. There was a non-significant decrease in the serum levels of SP-D after 3 months of radiotherapy (IMRT and 3D-CRT) compared with its serum levels immediately after RT. CONCLUSION: serum of levels IL-6 and SP-D can be used to diagnose the occurrence of early lung toxicity due to radiotherapy and the rate of recovery from radiation pneumonitis is apparent in case of IMRT than 3D-CRT.